[llvm] [RISCV] Move vector pseudo hasAllNBitUsers switch into RISCVBaseInfo.{h,cpp}. NFC (PR #67593)

[Philip Reames via llvm-commits]

================
@@ -2753,148 +2753,6 @@ bool RISCVDAGToDAGISel::selectSHXADD_UWOp(SDValue N, unsigned ShAmt,
   return false;
 }
 
-static bool vectorPseudoHasAllNBitUsers(SDNode *User, unsigned UserOpNo,
----------------
preames wrote:

Killing off this helper function hurts readability.  Please undo.  

https://github.com/llvm/llvm-project/pull/67593